It's a good start so don't put your sculpting skills down! I think Kiwi's brow-box ran higher, even with the hairline on the original head you're using. The only other problem you're going to have, to get a dead-on likeness, is that Kiwi's eyelids weren't heavy like Universal's Monster's was. He was pretty bright-eyed under the box on his forehead. Not sure what you could do about that, though?